Burns ended his list of imperatives to the Georgetown graduates with this memorable defense of the arts. In a speech that had drawn heavily on Abraham Lincoln's warning that the greatest threats to America come from within, Burns argued that the real defense of a nation lies not just in its military power but in the quality of its civilization. This line became one of the most quoted from any commencement speech of the decade. Burns had devoted his career to the proposition that understanding who we are as a people — through our music, our wars, our stories, our struggles — is essential to national survival. The arts, he argued, are not luxuries or decorations; they are the substance of what we are defending when we defend our way of life.